Question

Complete the identity. cos (alpha - beta)/cos alpha cos beta=?

Answer 1

When you see a formula like this, try to operate, so you will see some identities sooner or later. In this case, we have a substraction identity:

$\frac{cos ( \alpha - \beta )}{cos \alpha cos \beta }$ = $\frac{cos \alpha cos \beta + sin \alpha sin \beta }{cos \alpha cos \beta }$ = 1 + tan α · tan β

Answer 2

Answer:

When you see a formula like this, try to operate, so you will see some identities sooner or later. In this case, we have a substraction identity:

\frac{cos ( \alpha  -  \beta )}{cos  \alpha cos  \beta }  =  \frac{cos   \alpha cos  \beta + sin \alpha sin  \beta }{cos  \alpha cos  \beta }  = 1 + tan α · tan β

Step-by-step explanation: